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HelpTest Code HTLLC Human T-Cell Lymphotropic Virus Types 1 and 2 (HTLV-1/-2) Antibody Confirmation, Spinal Fluid
Reporting Name
HTLV -1/-2 Ab Confirmation, CSFPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Confirmatory detection of human T-cell lymphotropic virus types 1 and 2 (HTLV-1 and HTLV-2)-specific IgG antibodies in spinal fluid specimens that are consistently reactive by initial screening tests
Differentiating between HTLV-1- and HTLV-2-specific IgG antibodies present in spinal fluid
Method Name
Line Immunoassay (LIA)
Ordering Guidance
This confirmatory assay should be ordered only on spinal fluid specimens that are consistently reactive by an antihuman T-cell lymphotropic virus 1 and 2 (HTLV-1/-2) screening immunoassay. For an evaluation that includes both screening and confirmation, order HTLVC / Human T-Cell Lymphotropic Virus Types 1 and 2 (HTLV-1/-2) Antibody Screen with Confirmation, Spinal Fluid.
For testing serum specimens, order HTLVL / Human T-Cell Lymphotropic Virus Types I and II (HTLV-I/-II) Antibody Confirmation, Serum.
Necessary Information
Date of collection is required.
Specimen Required
Collection Container/Tube: Sterile vial
Specimen Volume: 0.5 mL
Specimen Type
CSFSpecimen Minimum Volume
0.2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| CSF | Frozen (preferred) | 30 days | |
| Refrigerated | 14 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
Reference Values
Negative
Interpretation
Negative confirmatory test results indicate the absence of both human T-cell lymphotropic virus types 1 and 2 (HTLV-1 and HTLV-2)-specific IgG antibodies in spinal fluid and a low probability of an HTLV-1/-2-associated neurologic disorder.
A reactive screening (enzyme immunoassay) result with a negative or indeterminate confirmatory (line immunoassay) test result suggests either a false-reactive screening test result or a seroconverting HTLV infection. Repeat testing with a new specimen can clarify the final infection status. Persistently indeterminate confirmatory test results indicate an absence of HTLV infection.
Positive results for HTLV-1 antibodies indicate the confirmed presence of HTLV-1 IgG antibodies in spinal fluid, based on 2 visible antibody bands that include gp21-I/-II band, or 3 or more bands, and the sum of the gp46-I and p19-I band intensity is greater than the gp46-II band intensity.
Positive results for HTLV-2 antibodies indicate the confirmed presence of HTLV-2 IgG antibodies in spinal fluid, based on 2 visible antibody bands that include gp21-I/-II band, or 3 or more bands, and the gp46-II band intensity is a) greater than the gp46-I band intensity and b) greater than or equal to the sum of the gp46-I and p19-I band intensity.
Indeterminate results indicate the presence of the gp21-I/-II band only or combination of any 2 bands without a detectable gp21-I/-II band. Patients with indeterminate test results with known risk factors for HTLV-1 or HTLV-2 infection should undergo repeat confirmatory antibody testing with a new specimen to determine final infection status.
Differentiation of HTLV-1 and HTLV-2 infection is not possible (ie, nontypeable HTLV antibodies) when the band intensity pattern does not meet the criteria of positive HTLV-1 or HTLV-2 antibody band intensity pattern.
Unreadable results indicate the presence of nonspecific background reactivity that is inhibiting the visualization of specific bands on the test strip. Repeat testing with a new specimen is recommended.
Invalid results indicate that nonspecific band reactivity is present. Submit another specimen for retesting if clinically indicated.
Day(s) Performed
Tuesday
Report Available
2 to 15 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
86689
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HTLLC | HTLV -1/-2 Ab Confirmation, CSF | 93744-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 604935 | HTLV-1/-2 Ab Confirmation, CSF | 93745-8 |
| 604945 | HTLV-1/-2 Bands | 93743-3 |
| 604946 | HTLV-1/-2 Discrimination | 93742-5 |
Forms
If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.